1. Technical Field
The present invention relates to a lock structure of a connector.
2. Background Art
FIGS. 10 to 13 show a lock structure of a connector disclosed in JP-A-2013-58358.
The lock structure is a structure which can lock a fitting state between connector housings of a connector 100 when fitting between the connector housings is completed, and which can release a lock state between the connector housings in order to detach the locked connector housings from each other. The connector 100 includes a pair of the connector housings, i.e. a first connector housing 110 and a second connector housing 120.
In the case of the lock structure in JP-A-2013-58358, the first connector housing 110 which is one connector housing is provided with a lock portion 113. The lock portion 113 has a lock arm 111 and lock release arms 112. In addition, as shown in FIG. 12, the second connector housing 120 which is the other connector housing is provided with a lock engagement part 121 engaged with the lock arm 111 when fitting between the connector housings is completed.
As shown in FIGS. 11 and 12, the lock arm 111 in the lock portion 113 is provided with a pair of flexible arms 111a, a connection part 111b and a lock protrusion 111c. Each of the flexible arms 111a extends from a place closer to a rear end of a housing body 114 of the first connector housing 110 toward a front end of the housing body 114. The connection part 111b connects distal end portions of the pair of flexible arms 111a to each other. The lock protrusion 111c is protrusively provided in a lower portion of the connection part 111b. 
As shown in FIG. 10, the housing body 114 of the first connector housing 110 is a part which has terminal receiving holes 114a receiving terminal metal fittings. The first connector housing 110 has a hood portion 115 which is substantially shaped like a cylinder and which covers an outer circumference of the housing body 114. The hood portion 115 defines, around the housing body 114, a housing fitting space 116 into which a distal end cylindrical portion 122 of the second connector housing 120 is fitted. The aforementioned lock engagement part 121 is a protrusion which is protrusively provided in an outer circumferential surface of the distal end cylindrical portion 122.
As shown in FIG. 12, each of the flexible arms 111a of the lock arm 111 is provided with a base end portion 111d and a spring piece portion 111e. The base end portion 111d rises up from an outer circumferential surface closer to the rear end of the housing body 114. The spring piece portion 111e extends from a distal end of the base end portion 111d toward the front end side of the housing body 114.
A distal end side (front end side) of the spring piece portion 111e can be deflected in a height direction (a direction of arrow Y1 in FIG. 12) of the first connector housing 110. In addition, the pair of flexible arms 111a are provided separately from each other in a width direction (a direction of an arrow X1 in FIG. 10) of the first connector housing 110.
The lock protrusion 111c of the lock arm 111 is a protrusion which protrudes toward the surface of the housing body 114 from the connection part 111b connecting the distal end portions of the pair of flexible arms 111a to each other. When fitting between the connector housings is completed, the lock protrusion 111c is engaged with the lock engagement part 121 of the second connector housing 120 as shown in FIG. 13. In this manner, the connector housings are restricted from moving in a detachment direction from each other. Thus, the fitting state between the connector housings is locked.
As shown in FIG. 12, the lock protrusion 111c of the lock arm 111 rides onto the lock engagement part 121 due to elastic deformation of the flexible arms 111a when the connector housings are being fitted into each other. In addition, when the fitting between the connector housings is completed, the lock protrusion 111c climbs over the lock engagement part 121 to move down to the back of the lock engagement part 121 due to elastic restoring force of the flexible arms 11a. Thus, the lock protrusion 111c is engaged with the lock engagement part 121.
As shown in FIG. 11, the lock release arms 112 of the lock portion 113 are provided to be paired and located outside the lock arm 111 in the width direction of the first connector housing 110. Each of the lock release arms 112 is provided with a release arm body 112a and a fulcrum portion 112b. The release arm body 112a extends from an end portion of the connection part 111b toward a rear end side of the first connector housing 110. The fulcrum portion 112b is provided in a lower part of a longitudinally intermediate portion of the release arm body 112a. In addition, free ends of the release arm bodies 112a located on the rear end side of the first connector housing 110 are connected to each other by an operating portion 112c. 
When the operating portion 112c is pushed down in a direction of an arrow Y2 as shown in FIG. 12, the free end sides of the pair of lock release arms 112 move down toward the housing body 114 side. When the fulcrum portions 112b abut against the outside surface of the housing body 114 as shown in FIG. 12, the lock release arms 112 swing with the fulcrum portions 112b as fulcrums. Due to the swing, the lock protrusion 111c is displaced in a lock release direction (a direction of an arrow Y3 in FIG. 12).
That is, the lock release arms 112 are swung around the fulcrum portions 112b so that the lock state carried out by the lock arm 111 can be released.
Incidentally, the lock protrusion 111c of the lock arm 111 rides onto the lock engagement part 121 when the connector housings are being fitted into each other. On this occasion, the lock release arms 112 provided integrally with the connection part 111b are also displaced due to deflection displacement of the flexible arms 111a. The operating portion 112c moves down toward the housing body 114 side even in such a situation.
In the lock structure disclosed in JP-A-2013-58358, the lock release arms 112 of the lock portion 113 are disposed outside the lock arm 111 in the width direction, as shown also in FIG. 10.
For this reason, the width of the lock structure is larger than the width of the lock arm 111. Therefore, there is a problem that the size of the first connector housing 110 may be increased due to the increase of the width of the lock structure.